888-19-7Relevant academic research and scientific papers
Transition-Metal-Free Deconstructive Lactamization of Piperidines
Romero-Iba?ez, Julio,Cruz-Gregorio, Silvano,Sandoval-Lira, Jacinto,Hernández-Pérez, Julio M.,Quintero, Leticia,Sartillo-Piscil, Fernando
, p. 8867 - 8871 (2019/05/28)
One of the major challenges in organic synthesis is the activation or deconstructive functionalization of unreactive C(sp3)–C(sp3) bonds, which requires using transition or precious metal catalysts. We present here an alternative: the deconstructive lactamization of piperidines without using transition metal catalysts. To this end, we use 3-alkoxyamino-2-piperidones, which were prepared from piperidines through a dual C(sp3)–H oxidation, as transitory intermediates. Experimental and theoretical studies confirm that this unprecedented lactamization occurs in a tandem manner involving an oxidative deamination of 3-alkoxyamino-2-piperidones to 3-keto-2-piperidones, followed by a regioselective Baeyer–Villiger oxidation to give N-carboxyanhydride intermediates, which finally undergo a spontaneous and concerted decarboxylative intramolecular translactamization.
Dopamine/serotonin receptor ligands. 10: SAR studies on azecine-type dopamine receptor ligands by functional screening at human cloned D1, D2L, and D5 receptors with a microplate reader based calcium assay lead to a novel potent D1/D5 selective antagonist
Hoefgen, Barbara,Decker, Michael,Mohr, Patrick,Schramm, Astrid M.,Rostom, Sherif A. F.,El-Subbagh, Hussein,Schweikert, Peter M.,Rudolf, Dirk R.,Kassack, Matthias U.,Lehmann, Jochen
, p. 760 - 769 (2007/10/03)
On the basis of the benz[d]indolo[2,3-g]azecine derivative 1 (LE300), structure-activity relations were investigated in order to identify the pharmacophore in this new class of ligands. Various structural modifications were performed and the inhibitory activities at human cloned D1, D2L, and D5 receptors were measured by using a simple fluorescence microplate reader based calcium assay. Subsequently, the affinities of active compounds were estimated by radioligand binding experiments, Deleting one of the aromatic rings as well as replacing it by a phenyl moiety abolishes the inhibitory activities almost completely. Contraction of the 10-membered central ring decreases them significantly. The replacement of indole by thiophene or N-methylpyrrole reduces the inhibitory activity, whereas replacing the indole by benzene increases it. Finally, the hydroxylated dibenz[d,g]azecine derivative 11d (LE404) was found to be more active than the lead 1 in the functional calcium assay as well as in radioligand displacement experiments.
New bis-indolic macrolactams
Henin,Noe,Laronze
, p. 1693 - 1703 (2007/10/03)
Treatment of several ω-halogenoamides, derived from tryptamine, with powdered potassium hydroxide in 1,2-dimethoxyethane in the presence of 18-crown-6, resulted in intramolecular and/or bimolecular cyclization, depending on the length of the chain and dilution conditions, to give macrocyclic compounds. Some of them were converted by a Bischler-Napieralski reaction, followed or not by reduction, to new tetracyclic derivatives of β-carbolines.
